1993 Specific year concerns
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- #23
I've been doing some more reading on other issues - and their symptoms/resolutions and I'm almost convinced it's a trans issue. There seems to be downshifting issues with these vehicles - could be a combination of solenoids/connectors/fluid (etc). I think mine is just starting to exhibit the problems. Being at a stand still (almost always happens when first started) and the vehicle refuses to go, but very slowly inches forward, seems to be the common problem.
This does bring me to some other questions, though -
ECT - when pressed, nothing seems to happen? I didn't look closely, is there supposed to be a dummy light and activation of?
I can see on the cluster there are 3 diff lock lights... being that this is a 93 it has a VC and am reading the 91-92's don't have it. I've read the 91-92 have a center diff lock, and have read that others have installed a diff lock switch on the dash.... this brings me to a couple other questions - is there a center diff lock (other than the VC) on the 1993 and the dummy light is left over from another year, or is there a diff lock in the transfercase that isn't utilized because of the VC?
This does bring me to some other questions, though -
ECT - when pressed, nothing seems to happen? I didn't look closely, is there supposed to be a dummy light and activation of?
I can see on the cluster there are 3 diff lock lights... being that this is a 93 it has a VC and am reading the 91-92's don't have it. I've read the 91-92 have a center diff lock, and have read that others have installed a diff lock switch on the dash.... this brings me to a couple other questions - is there a center diff lock (other than the VC) on the 1993 and the dummy light is left over from another year, or is there a diff lock in the transfercase that isn't utilized because of the VC?
AS far as the ECT button: Nothing noticeable will happen sitting still. It is kind of like a "boost" button. When pressed, the transmission will give you slightly more power and not upshift at the normal points. Little more power when needed on demand. Some run with it always on, some rarely/never use it, some (like me) use it sometimes when merging onto the freeway or uphill and such.
When engaged, you should see a little green illuminated "pwr" in your cluster just below the vertical row of indicators (P N D....just below those)
Our center diff lock engages when in 4W Lo automatically. The 91-92 models had no lockers, but did have the center diff lock button to engage on demand (even in high).
search for for the cdl switch mod. The 91-92 cdl switch fits our dashes, and the plug is there behind the dash to use. Plug and play and you have the mod (with a 7 pin mod to do also behind the panel by your left foot...again search for mod details...quick and easy).
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You know why "O'doyle Rules!"? Because he drives a 93 80 series.
One easy check is the kickdown cable at the throttle under the hood. I drove mime for two years without messing with it and was getting high 12's, low 13's mpg. I adjusted it and now my trans is useful. It used to drop a gear every time I touched the gas. I had no throttle without it downshifting. After adjusting (took a couple minutes), I am getting high 13 to 14.2mpg and have about 60-70% of gas pedal travel before it downshifts.
One easy check is the kickdown cable at the throttle under the hood. I drove mime for two years without messing with it and was getting high 12's, low 13's mpg. I adjusted it and now my trans is useful. It used to drop a gear every time I touched the gas. I had no throttle without it downshifting. After adjusting (took a couple minutes), I am getting high 13 to 14.2mpg and have about 60-70% of gas pedal travel before it downshifts.
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- Thread starter
- #26
I did read about most of that - my "pwr" light isn't coming on (could be a light/electrical issue, could be something else) and is why I was asking
Is the diff lock light supposed to illuminate when thrown in 4L? I guess that was my question. I can throw it in 4L and feel that the front tires struggle a bit at full lock with the wheel (as in - the lock is in place) that isn't there in 4H.
Guess yet another question - I pulled the motor off the front locker first - didn't seem to be 'frozen' up (moved freely, with tension, and could feel the 'stopping' points of it) and I could feel the gear in the diff that had a tiny bit of movement (guessing without moving it wouldn't slide/lock easily)... upon reassembly I'm still getting both diff lock lights flashing when in 4L - so I'm wondering if the rear fails, do both lights flash regardless? My assumption is that it isn't that complicated - that the plug on the diff itself (not the motor) is a simple grounded switch, so that when the motor moves the lock, the switch grounds and the light turns on (similar to my 88 Corolla Alltrac, which is silly simple - switch activates 2 VSV's and the light illuminates when the vacuum switch actually moves the lock... the CDL switch is actually independent of the light itself on the dash). I have a feeling if I were to pull the connector and jumper it, then the front diff light would stay illuminated and I actually have another problem...
Also read that cleaning the contacts (external and internal) may do wonders to making the motor work, if that's the problem.... and depending on the answer to the last question may be my next endevour...
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- #27
As an addition to my past thoughts - I pulled the wheel again, pulled the motor out - set the key to 'on', 4L, and diff locks on, then jumpered the on-diff switch connector - diff lock was flashing. Plugged the motor in and tried again - the motor didn't move (I visually looked to see where the C clip was based on the housing) but the diff lock light stayed on (remember the connector was jumpered). So there's an issue with the motor.
Gotcha.
Yes, the CDL light should come on (once it locks up) when you shift to 4lo...may take a few feet to engage then come on.
Both locker lights flashing may mean neither engaging, that's what they do until they engage.
My rear flashes no matter what though, even though it locks up just fine (some issue in the switch). Easiest way to test if engaging is to get the wheels off the ground (jack stands) and lock front, then rotate the wheels by hand. you'll know if they lock up.
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- #29
There's an obvious electrical issue at this point. I pulled the front motor out - again and ran a bunch of tests..... I pulled the gear system out then bench tested it with a spare battery and the motor turns both ways freely and nicely. Then put the gear system back (and being as quick as possible to pull power each direction) made sure the gear system turned as well - which it did nicely and freely. connected it electrically to the rig and getting nothing - so it's an issue somewhere in the system.
The 30A fuse is good, but I'm missing the relay box cover in the engine compartment. I might even be missing a couple of relays, I'm not sure. The owners manual I have shows (from the front back) 4 relays, in a 2x2 manner... I have the front 2 and the rear 2 are MIA (unsure if that's other features I don't have, or what). The manual doesn't cover that, guess I'll have to find an FSM...
The 30A fuse is good, but I'm missing the relay box cover in the engine compartment. I might even be missing a couple of relays, I'm not sure. The owners manual I have shows (from the front back) 4 relays, in a 2x2 manner... I have the front 2 and the rear 2 are MIA (unsure if that's other features I don't have, or what). The manual doesn't cover that, guess I'll have to find an FSM...
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- #30
At this point I think I'm mostly talking to myself - but sometimes I do that (I had a couple pages of thoughts/findings/updates about my AE95 Alltrac CDL as well on another forum that nobody was following, given that system is a vacuum based lock, it's completely different)... However maybe some day someone can reference this as helpful for diagnostic purposes? I dunno.
I downloaded a 1994 FSM and assuming it's close enough. From what I gather - the front/rear locks will ONLY work if the lock ecu sees that the system is in 4L and that the center diff lock is locked. As previously mentioned, I'm not getting the CDL light - and after more research, I'm guessing my CDL switch is bad (or at least needs to be pulled and cleaned).... so I can feel the center is locked (I'm pretty sure, based on tire scrubbing at wheel lock) but the light isn't on - which I would assume means the lock ecu isn't registering that the center is actually locked, which isn't sending the signal to actually activate the lock motors.
I'm also looking into/thinking about the CDL switch (using the hazard button method, I might even have one lying around) and the pin 7 mod.... which has me thinking - the pin 7 mod from what I gather (I haven't actually read into exactly what to do quite yet) is eliminating a signal so that you can override it via a switch instead of through the 4L switch activation - what if you were to use a standard relay that could read the signal from the CDL switch to override the pin 7 signal.... or leave it in place so that if you go in 4L without using the CDL lock, it would lock the center as normal? Probably unnecessary, but food for thought I guess...
I downloaded a 1994 FSM and assuming it's close enough. From what I gather - the front/rear locks will ONLY work if the lock ecu sees that the system is in 4L and that the center diff lock is locked. As previously mentioned, I'm not getting the CDL light - and after more research, I'm guessing my CDL switch is bad (or at least needs to be pulled and cleaned).... so I can feel the center is locked (I'm pretty sure, based on tire scrubbing at wheel lock) but the light isn't on - which I would assume means the lock ecu isn't registering that the center is actually locked, which isn't sending the signal to actually activate the lock motors.
I'm also looking into/thinking about the CDL switch (using the hazard button method, I might even have one lying around) and the pin 7 mod.... which has me thinking - the pin 7 mod from what I gather (I haven't actually read into exactly what to do quite yet) is eliminating a signal so that you can override it via a switch instead of through the 4L switch activation - what if you were to use a standard relay that could read the signal from the CDL switch to override the pin 7 signal.... or leave it in place so that if you go in 4L without using the CDL lock, it would lock the center as normal? Probably unnecessary, but food for thought I guess...
Sounds like you're in the right direction. I know sometimes it can feel like your postings on here end up being just a streaming consciousness! Honestly, it sounds like you're a more advanced mechanic than I am, I'm just familiar with a lot of the differences.
But I think you're right. Without center diff locking up, lockers won't engage, so that sounds like your starting point.
But I think you're right. Without center diff locking up, lockers won't engage, so that sounds like your starting point.
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- #32
I'm good at making things work - which includes weird diagnostics and how to 'resolve' them, plus pretty good at wiring. I have purchased a lot of vehicles at low prices with problems, sometimes surprisingly basic things that cause major problems.
I'm not good at transmissions nor differentials.... mostly because everything I've owned hasn't needed work on those, or they were FWD/MR transaxles - which are a dime a dozen (literally, $50 is expensive for a C series transmission) so if one goes out, you just throw another in.
For me this is a good learning curve - now I will know that the first thing to do on these is ensure the CDL is activated, because as far as I know the front/rear motors might be perfectly fine (although I will say the front did need to be pulled and the gearset shaft lubed, it was stiff)
I'm not good at transmissions nor differentials.... mostly because everything I've owned hasn't needed work on those, or they were FWD/MR transaxles - which are a dime a dozen (literally, $50 is expensive for a C series transmission) so if one goes out, you just throw another in.
For me this is a good learning curve - now I will know that the first thing to do on these is ensure the CDL is activated, because as far as I know the front/rear motors might be perfectly fine (although I will say the front did need to be pulled and the gearset shaft lubed, it was stiff)
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Correct, if the actuator motor is running, CDL locking and the light isn't on, most often it's the switch. It's not cheap from Toyota, but is available aftermarket, order a backup light switch for a 2000 5spd Tacoma. Lots of CDL info in this thread: CDL Actuator Fun
The CDL has to be working (or the switch connection jumped so the light is on) before the axle lockers will activate.
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- #34
In my research I had seen that it could have been one of 2 switches - the CDL or the 4L (which wouldn't have even activated the CDL actuator). In any event, I was hoping/banking on the CDL switch since I thought I could feel the CDL activated.
So - crawled under the rig and I could only see 1 of the 2.... wasn't 100% sure which it was, so I pulled the connector, jumpered it - and the center diff lock light lit up. Ok - turned on the lockers, and the front locked. Rear did not (not surprising).
Pulled the switch and tested it with an ohm meter - nothing. It was visually very clean, but non functional. Used some carb cleaner and rolling/pushing it over and over and I started to see the ohm meter react, but never a 'buzz' to tell me there was continuity. Kept at it - carb cleaner and pushing/rolling and it started to buzz a little.... kept at it and it got pretty consistent.
Put the switch back in the rig (hand tight), connected it - and the CDL light came on. Whew. Tightened it back down.
Now on to the rear. (I feel like I should be taking photos as I go)
So - crawled under the rig and I could only see 1 of the 2.... wasn't 100% sure which it was, so I pulled the connector, jumpered it - and the center diff lock light lit up. Ok - turned on the lockers, and the front locked. Rear did not (not surprising).
Pulled the switch and tested it with an ohm meter - nothing. It was visually very clean, but non functional. Used some carb cleaner and rolling/pushing it over and over and I started to see the ohm meter react, but never a 'buzz' to tell me there was continuity. Kept at it - carb cleaner and pushing/rolling and it started to buzz a little.... kept at it and it got pretty consistent.
Put the switch back in the rig (hand tight), connected it - and the CDL light came on. Whew. Tightened it back down.
Now on to the rear. (I feel like I should be taking photos as I go)
Nice job!! Yeah, this is looking like it's turning into a build thread...pics or it didn't happen!
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- #37
This switch looked very familiar to me - I had done a 5sfe/S54 swap into an AW11 and the reverse connector (among just about everything else - and in that vehicle I payed close attention to NOT cut any body/factory harness to couple the body/engine harnesses) looked the same. Per Rock Auto it looks to be the same, and since it's just a simple on/off switch, resistance values wouldn't be impacted. Looks like $15.75 from rock auto. My guess is all FWD/MR cars with a 5 speed manual from about 91/92/93 (depending on model) up would be the same switch. Doesn't surprise me since it's easier/cheaper to use the same part across multiple platforms and not have to pay to re-engineer "the wheel", so to speak.
You would think with having a nice camera on my phone plus having 2 DSLR's and a lot of lenses that I would actually document something...
This is where things get weird. I'm guessing testing lockers on dry pavement is a no-no.... most of my testing is done in my driveway (about 40-60 feet, I really have no idea) which is gravel.....
drove to someone's house for lunch after the above information was provided.... and was ~50 yards from her driveway. Threw it in 4L (CDL popped on), threw the locker switch on (front locked, rear did not) and drove slowly to her house.... It almost refused to turn right, and turning left it was fine with. That bothered me, so about 10 feet from her driveway I stopped, put it in neutral, turned the lockers off, then put it in 4H, then drive.... and the CDL light stayed on, ABS light stayed on, and the steering issue prevailed. Tried a few combinations, but pulled into the driveway to go on a walk.
Got back - and had to head home.
Same issue (even though in 4H and lockers off - center diff light was on as was ABS).... tried forward, backward.... so figured I would try to hit a bump or something, backed up, turned hard (out of the drieway) and "POP"..... lights went out, everything was 'back to normal'.
Got back to my house, and in the gravel driveway.....
put it in 4L and the CDL/ABS lights popped on.
put it in 4H and the CDL/ABS lights popped off
put it in 4L and the CDL/ABS lights did not pop on - put it in reverse (nothing), then neutral then drive - and it popped on.
switched the locker on.... and the REAR locked, front did not
turned lockers off, and they turned off.
turned lockers on, and the front hesitated, but turned on, then after moving a foot the rear locked.
turned lockers off, and the rear wouldn't let go
turned lockers on, and then off, and the rear let go but the front wouldn't
My guess:
1) the CDL switch is bad (I could hear the relays turning on and off like crazy), which my multimeter was already telling me
2) the rear motor is tight, needs to be pulled/cleaned
3) the components just need to be used a little bit, turned on/off regularly to get movement in them
4) maybe the diffs all need new fluid
As a side note - the plug wires arrived (been dealing with the diff's instead, lately) so I plan to do a compression test - then install all components (plugs, wires, cap, rotor). I have a sneaking suspicion the engine isn't original - or if it is, it's been pulled/rebuilt. I'll check the vin and mount bolts to see if they're marred (no smoking at all, not even at start up, strong oil pressure, essentially no leaks... and 291k miles....)
Ordered a keyless entry/remote start and will install that at some point in the future (I don't trust the key to be used that much longer, so I don't use it in the doors...)
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- #38
and now the low idle/rough running (low rpm's) issue has come back. with a nasty vengence:
Rough idle (around 500) - rythmic as if a specific cylinder is down
Really rough acceleration - up to about 2700 rpms, then it's perfectly fine
Zero roughness when very partial throttle or off throttle
This morning when I went to move the truck to the other side of the driveway, although still running on the 'cold circuit' the issues were gone.
So this isn't 100% unexpected. I still plan to run a compression test. Given what the weather has been doing and how it's acting - I don't think it's a head gasket. I think it's electrical. I tried playing around/messing with the AFM and no change. Unplugged the TPS - and although I could hear a change, the 'problem' didn't change. I think it's ignition - could be cap/rotor/wires and/or the coil.
I have started by pulling the cap, rotor, and wires. They are showing their age. Cap/rotor aren't brass (which is fine, just need to be replaced more often) and are showing a lot of corrosion:
The rotor is worse, with the entire end of it marred up
Probably hard to see in this photo, but many wire sets (factory especially) will show the year they were made, these are from 1999:
On the plus side - it is very dry inside the dizzy... I'll be doing a resistance test on the coil here soon as well.
As for the 4L switch, I ordered the 92 MR2 reverse switch (for about $18 through Amazon prime) and will come back stating if it's the same (or good enough) or not.
Rough idle (around 500) - rythmic as if a specific cylinder is down
Really rough acceleration - up to about 2700 rpms, then it's perfectly fine
Zero roughness when very partial throttle or off throttle
This morning when I went to move the truck to the other side of the driveway, although still running on the 'cold circuit' the issues were gone.
So this isn't 100% unexpected. I still plan to run a compression test. Given what the weather has been doing and how it's acting - I don't think it's a head gasket. I think it's electrical. I tried playing around/messing with the AFM and no change. Unplugged the TPS - and although I could hear a change, the 'problem' didn't change. I think it's ignition - could be cap/rotor/wires and/or the coil.
I have started by pulling the cap, rotor, and wires. They are showing their age. Cap/rotor aren't brass (which is fine, just need to be replaced more often) and are showing a lot of corrosion:
The rotor is worse, with the entire end of it marred up
Probably hard to see in this photo, but many wire sets (factory especially) will show the year they were made, these are from 1999:
On the plus side - it is very dry inside the dizzy... I'll be doing a resistance test on the coil here soon as well.
As for the 4L switch, I ordered the 92 MR2 reverse switch (for about $18 through Amazon prime) and will come back stating if it's the same (or good enough) or not.
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- Thread starter
- #39
Per the FSM, Primary coil (cold) should read 0.36-0.55 and the secondary coil (cold) should read 9.0-15.4k
The primary coil is reading 0.7 and the secondary is reading 11.66k
FSM states if either is outside of range, to replace it. So whether this is 'the' problem or just 'another' problem.... there is one found:
Guess I'm on the hunt for a coil now too
The primary coil is reading 0.7 and the secondary is reading 11.66k
FSM states if either is outside of range, to replace it. So whether this is 'the' problem or just 'another' problem.... there is one found:
Guess I'm on the hunt for a coil now too
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Maybe, but, get under the rig, where you can hear/touch the rear actuator, have a helper switch the rear locker switch, with each activation (on and off) the actuator motor should briefly run. If this works, jack up the rear axle, lock the rear and turn a tire, within a few degrees of rotation should hear/feel it lock, lock/unlock a few times to confirm.
When the lockers are not needed, tires have traction, it's difficult to get them to work. Once locked, they will bind, takes some maneuvering to get them to unlock. So most times it easiest to test with the wheels in the air. On the trail, when lockers are needed, tires have slip, they lock right up. If it works every time in the air, it will work when needed on the trail.